2 * Small pcap precompiler
3 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2
7 * as published by the Free Software Foundation
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <sys/types.h>
21 int main (int argc, char ** argv)
23 struct bpf_program filter;
29 printf ("Usage: %s <expression>\n", argv[0]);
33 pc = pcap_open_dead(DLT_EN10MB, 1500);
34 if (pcap_compile(pc, &filter, argv[1], 1, 0) != 0) {
35 printf("error in active-filter expression: %s\n", pcap_geterr(pc));
39 printf("/* precompiled expression: %s */\n\n"
40 "static struct bpf_insn pktfilter_insns[] = {\n",
43 for (i = 0; i < filter.bf_len; i++) {
44 struct bpf_insn *in = &filter.bf_insns[i];
45 printf("\t{ .code = 0x%04x, .jt = 0x%02x, .jf = 0x%02x, .k = 0x%08x },\n", in->code, in->jt, in->jf, in->k);
48 "static struct bpf_program pktfilter = {\n"
50 "\t.bf_insns = pktfilter_insns,\n"
51 "};\n", filter.bf_len);